Release v0.4.1

Added

• Shutdown button: Power icon in the header bar initiates graceful server shutdown via POST /api/server/shutdown, triggering the same shutdown sequence as Ctrl+C (SIGINT)
• Backend unavailable page: When the backend is unreachable, the frontend shows a "Server Unavailable" page instead of silently falling into the first-run experience; automatically recovers when the backend comes back online
• Theme flash prevention: Dark/light theme is now applied in index.html before React loads, eliminating the flash of wrong theme on page load
• Task History deep links: Scan entries in the Task History table are now clickable links (e.g., "Scan #42") that navigate directly to the Browse page with the correct root and scan pre-selected via URL parameters (/browse?root_id=X&scan_id=Y)

Fixed

• Fix SQLite WAL/SHM files not being cleaned up on shutdown by properly closing the connection pool; the pool is now taken out of its global slot during shutdown, a WAL checkpoint is performed, and all connections are closed so SQLite removes the -wal and -shm files
• Fix react-refresh/only-export-components lint warnings in ScrollContext.tsx by exporting the context object directly instead of aliasing the Provider

Changed

• Upgrade static_vcruntime from v2 to v3 and add recommended +crt-static rustflag for Windows MSVC builds, ensuring binaries work on machines without the Visual C++ Redistributable installed
• Move AppState from api/routes/scans.rs to its own api/routes/state.rs module for better separation of concerns